Between April and June, a deadly heat wave struck large swaths of northern India. Birds dropped dead from the sky. Demand for electricity skyrocketed. Forest fires raged in the Himalayas.

And at an Amazon facility on the outskirts of the capital New Delhi, in the dusty industrial town of Manesar, Rajesh Singh remembers his colleagues at the loading dock fainting around him.

“It happened so frequently, I thought there was a virus doing rounds,” Singh says.

Singh, 24, and a handful of his colleagues met NPR reporters at a roadside café in mid-June, giving up the chance to make a day’s overtime pay of the equivalent of around $14. It beefs up his earnings that come to around $120 a month. The pay might be decent in a village or provincial town, but it’s low for these parts around Delhi.